Meanwhile, two suspected Al-Qaeda militants were arrested in a raid on a house where they were hiding, said a security official.

The raid took place "near the intelligence headquarters" where 19 soldiers had been killed in an August 18 rocket attack which the authorities blamed on Al-Qaeda.

"There was an exchange of gunfire during (Sunday's) raid but no one was hurt," the official said, requesting anonymity.

Yemeni security forces have been on heightened alert since the intelligence headquarters attack. Six other suspected militants were arrested on Thursday and Friday.

Al-Qaeda loyalists have carried out a spate of deadly attacks against the Yemeni security forces and their militia allies since President Abdrabuh Mansur Hadi came to power earlier this year pledging to crush the militants.

Al-Qaeda had taken advantage of a nearly year-long uprising against Hadi's predecessor, veteran strongman Ali Abdullah Saleh, to seize large swathes of the south and east.

In an all-out offensive launched in May, the army retook a string of towns in Abyan province, which neighbours Aden to the east.